Choose which blackberry plants you will grow. Tie trailing blackberries to a trellis. Erect blackberries do not require a trellis.
Prepare a place for your blackberry plants. The site should be located in full sun. Dig an 8-inch hole for each plant.
Work 2 inches of composted manure and 2 inches of organic soil conditioner into the hole.
Place a trellis at the back of the hole if planting trailing blackberries.
Shake off excess soil from the roots of the plant. Place a few inches of water in a shallow dish. Set the roots in the dish for two hours.
Trim the top of the plant to 6 inches tall. Put the plant in the hole and back fill until the hole is nearly 2/3 full.
Water the bush well so that the soil settles. Finish filling the hole with the soil and water again.
Mulch around the plants to keep the moisture intact. Use an organic mulch like pine straw or wood chips. Mulch about an inch deep around your bushes. A 6-inch diameter is sufficient.
Tie a few canes to the trellis if using trailing blackberries. Use some yarn or string and tie the canes loosely. Check the plants every few months and adjust the string to allow for growth. A simple bow is easy to tie and untie.
Fertilize the blackberry bushes once in spring and once in the summer. Use a 10-10-10 fertilizer.